Submersible pump



Feb. 20, 1962 H. w. KAATZ 3,021,788

SUBMERSIBLE PUMP Filed May 2, 1957 2 Sheets-$heet 1 l 1 29 55 I l INVENTOR.

HEezaEer W. K4472 BY M 5,4414% A TTOENE Y5 Feb. 20, 1962 H. w. KAATZ 3,021,788

SUBMERSIBLE PUMP Filed May 2, 1957 2 Sheets-Sheet 2 I N VEN TOR. HEB/552T M/ /(4A TZ BY BM W,

H W+M 4 TTOEA/EYS.

can Crucibie Products Company, Lorain, Ohio, a conporation of (thin Filed May 2, 1957, Ser. No. 656,630 8 Claims. (#Cl. 103-25) This invention relates to pumps and in particular to submersible pumps which are adapted to be automatically actuated or deactuated in response to the level of the liquid which collects about the pump. This application is a continuation-in-part of my co-pending application Serial No. 493,631 filed March 11, 1955, now Patent No. 2,910,003.

It is a general object of my invention to provide an improved submersible pump which is compact and has increased operational etficiency and economy. Another object is to provide a centrifugal pump having a back shrouded impeller in which the thrust otherwise acting on the back shroud, shaft and bearings and the bearings are protected from the liquid being pumped and deleterious matter therein. A further object is to provide a submersible centrifugal pump having a downwardly opening inlet having means to both support the pump and protect the impeller from the dirt, sand and other deleterious matter which collects on the bottom of the sump or bilge and underlies the inlet. Other objects are to provide a submersible pump in which backfiow of liquid into and through the volute when the pump is deactuated is prevented and the self-priming of such a protected pump is ensured and to provide efiicient, inexpensive and easily and economically replaceable valve means to control the discharge orifice of a pump volute so as to prevent backfiow and/or to protect the volute from surge pressures when the pump is deactuated as in response to a reduction in volute pressure upon completion of the pumping cycle.

These and other objects and advantages of my invention will appear from the following description of preferred and modified embodiments thereof, reference being had to the appended drawings in which:

FIGURE 1 is an elevation partly in section of a pump embodying a preferred form of my invention and control therefor.

FIGURE 2 is a horizontal section of the pump and control of FIGURE 1 viewed along the line 2-2 of FIGURE 1, except that a fragmentary portion of the top of the volute chamber is shown in full plan adjacent the discharge outlet.

FIGURE 3 is a partial view of a modified form of bottom assembly for the pump of FIGURE 1.

FIGURE 4 is an exploded view of the check valve shown in FIGURE 2.

FIGURE 5 is a vertical section of the air lock relief valve viewed along the line S5 of FIGURE 2.

Referring now to the drawings and particularly FIG- URES 1 and 2 thereof, a pump embodying a preferred form of my invention is shown in conjunction with an automatic control therefor, although it is to be understood that my pump may be used with other controls, either automatic or otherwise, and other controls may be adapted for use with my pump. Further, my pump may be used with controls which are secured to the pump housing, as shown, or with controls which are within the pump housing or separated therefrom and connected therewith by suitable pipes and/or conduits.

A pump embodying a preferred form of invention comprises a housing 1, preferably of cast bronze, which forms the sides 2 and top 3 of the volute chamber. The top of the housing 1 is provided with an annular machined surface 5 and abutment 6. A substantially cylindrical cover or motor chamber housing 7 having a flange 8 with a beveled inner edge 9 and machined underside 10 is adapted to be secured to the housing 1, with surfaces 5 and Ill juxtaposed, as by screws 11 and defines the sides and top of the motor chamber 12. A seal or gasket 13 is interposed between the housings 1 and 7 adjacent the bevel 9 and prevents liquid from flowing into or out of the motor chamber 12. A motor 15 is mounted within the chamber 12. The top 3 of the housing 1 is provided with a hollow boss 16 which is concentric with the motor 15 and housing 7. The motor shaft 18 extends from the motor, through the boss 16 into the volute chamber 4 and is supported within the boss by a suitable bearing 19 coaxially aligned with the upper bearing 19a in the housing 7 in which the upper end of the shaft 18 is journalled. An impeller 22 is secured to the lower or volute chamber end of the shaft 18. The impeller 22 is preferably a concentric centrifugal impeller comprising blades 23 and a back shroud 24. The impeller may, as shown, be fully shrouded, in which instance a fiat plate 25 ha ing a central aperture 26 is secured to the underside of the blades 23.

An annular depending skirt or flange 28 which is preferably formed inte ral with the volute chamber top 3, depends downwardly therefrom toward the impeller 22. The depending edge of the annulus 28 is spaced slightly from the back shroud 24 of the impeller and the periph cries of the annulus and impeller are substantially aligned. A labyrinth seal 29 is preferably provided between the annulus 28 and back shroud 24 and vacuum bleed holes 30 are provided in the back shroud of the impeller and.

lead from the eye of the impeller to the space 31 above the impeller.

The vacuum bleed holes 30 and labyrinth seal 29 cooperate to permit the partial evacuation of the space 31, without undue reduction of the efficiency of the pump due to excessive recycling of the liquid being pumped across the back shroud and through the vacuum bleed holes. The partial evacuation of the space 31 reduces the downward thrust exerted upon the impeller 22 and consequently upon the bearings 19, aiding pump efiiciency pro tanto. The downward thrust, which is in part effectively and efiiciently relieved by the aforesaid vacuum bleed holes and labyrinth seal, results from the pressure differential which would otherwise exist across the impeller back shroud 24 during operation of the pump. This pressure differential results from the vacuum which is developed at the eye of the impeller, when it is rotated by the motor. holes has reduced the thrust on the impeller by as much as seventy-five percent.

A conventional running seal 32 is preferably disposed within an enlarged portion of the boss 16 adjacent the hub of the impeller and prevents the flow of liquid into or out of the motor chamber 12.

In order to obtain maximum pump efiiciency with maximum compactness I prefer that the'pump embody a developed volute although volutes of other shapes may be used. Accordingly, the volute housing 1, see FIG- URE 2, is not concentric but rather is of such a shape that the volute, as the same is defined by the side walls 2 of the housing 1 and the outer edge of the impeller In tests the use of the vacuum bleed.

The assembly 34 is adapted to support the motor pump unit, define the underside of the volute chamber and to prevent debris and other foreign matter from reaching the impeller. Preferably and especially the assembly 34 is also adapted to prevent the grit, dirt, and sand which normally lie on the bottom of the bilge, sump, etc. and particularly that which directly underlies the pump inlet from being drawn into the impeller with resultant deleterious eifect on the pump and pumping system. To this end the bottom assembly may conveniently comprise a circular base plate 37 which is preferably provided with a groove 38 on its upperside near its periphery, a bottom plate 40 adapted to cover the open end of the housing 1 and having in its underside a similar groove 41 in coaxial alignment with the groove 38 and an annular sturdy, perforate sheet metal screen 43, the lower and upper edges of which are disposed in the grooves 38 and 41 respectively. The screen 43 may be from about A to /8 as high as its diameter depending on the size of its perforations and the proportion of perforate to solid area consistent with desirable mechanical strength, low velocity flow therethrough, effective screening function, freedom of flow under variously burdensome conditions of use and the disposition of the eye of the impeller desirably proximate the bottom of the sump or bilge to be evacuated.

The plate 40 defines the underside of the volute chamber and is provided with an aperture 44, concentric with the eye, of the impeller 22, through which the liquid to be pumped reaches the impeller. The plate 37, as set forth above, prevents dirt, sand, grit and other matter lying on the bottom of the sump, bilge tank etc. and especially directly under the pump from being sucked into the pump. The screen 43 prevents other debris and foreign matter from reaching the impeller and is of sufficient strength and shape to support the weight of the pump without collapsing, to the end that the entire bottom assembly may serve as a support or stand for the motor pump unit with the plate 37 resting on the bottom of the sump, bilge or receptacle to be evacuated. Auxiliary legs (not shown) may be secured to those portions of the bottom plate 48 and housing which, because of the shape of the volute, extend beyond the screen, as for example, at the discharge openmg.

Another convenient form of bottom assembly adapted to obtain similar advantages as that already described is shown, for example, in FIGURE 3 and indicated generally at 34 Assembly 34" includes a circular base plate 37, a bottom plate 49' and a screen 43. The plates 37' and 40' are similar to the plates 37 and 40 except that they have no circular grooves in their surfaces and the screen 43 is the same as the screen 43 except that it is assembled with its upper edge bearing upon the under surface of plate 40' and its lower edge lying externally of and against the edge of the base plate 37'. The assembly 34 is held in position by a plurality of Z-shaped reinforcement members 45 having one leg underlying and being secured to the base plate 37' and the other leg detachably secured to the housing 1, as by screws 35.

The motor pump unit shown is also provided with a control C, which is adapted to actuate the pump at a predetermined maximum liquid level and to deactuate the pump at a predetermined minimum liquid level, although motor pump units embodying my invention may be controlled by other means. To accommodate the control, I provide a 'boss 46 having an aperture 47 on the side wall 2 of the volute and a boss 48 having aperture 49 on the motor chamber housing 7. The respective faces of the bosses 46 and 48 lie in the same vertical plane and the bosses are preferably located near the beginning of the volute in order to save space.

Briefly the control shown includes high and low pressure responsive diaphragms 50 and 51, respectively, maintained in spaced relationship by switch ring 52 and mounted on the motor pump unit so that the high pressure diaphragm covers the apertures 47 and, 49. A downwardly opening skirt plate 53 is mounted over the diaphragm 51. A single throw normally open switch 55, having operating plunger 56, is disposed within the switch ring and con nected, by suitable leads, in series with the motor 15 and a power source.

The switch 55 is resiliently mounted, as on the bent and shaped spring 57 (FIGURE 2) between the diaphragms 5'0 and 51 so that switch and spring may be displaced in a horizontal plane by and between the diaphragms. The spacing between the diaphragms, the shape and disposition of the spring, and the size and operating characteristics of the switch and plunger are such that when only one diaphragm is displaced toward the other, by the pressures acting thereon, the switch and spring are merely displaced or pushed by the said diaphragm toward the other diaphragm and the plunger 56 is not depressed and the switch and circuit remain open; but when both diaphragms are displaced toward each other, to the maximum per mitted and with a force greater than the operating force of the switch, the spring is squeezed, depressing the plunger 56 and closing the switch and circuit and actuating the pump. The area of the diaphragms and switch operating force is such that diaphragm 51 responds to the static pressure of predetermined minimum liquid level to have a maximum displacement and exert a force greater than the operating force of the switch, whereas diaphragm 53 does not so respond to such a minimum liquid level but rather responds to the static pressure of a predetermined maximum liquid level, so long as such pressure is less than the volute pressure of the, pump when liquid is pumped and therefore to said volute pressure, to have a maximum displacement and exert a force greater than the operating force of the switch. The diaphragm 50 is acted upon by and responds to pressures existing within the volute and diaphragm 51 is acted upon and responds to pressures existing within the skirt 53.

Thus in operation the control is disposed in a sump, for example, together with the pump of which it is a part. As water collects in the sump the level rises enveloping the open end of the skirt 53 and exerting a hydrostatic pres sure on the diaphragm 51, which when the level reaches the predetermined minimum level 1, for example, is displaced toward the diaphragm 51') to the maximum degree permitted and with a force greater than the operating force of the switch. The switch is also displaced toward the diaphragm 50 but is not actuated as the diaphragm '50 does not respond (at least sufficiently). to the same liquid level. Water continues to collect in the sump until the level thereof reaches a predetermined maximum 7", for example, the hydrostatic pressure of which is sufiicient to displace diaphragm 50 toward diaphragm 51 to the maximum degree permitted, and with a force greater than the operating force of the switch. This squeezes the spring 57 depressing the plunger 56-and actuating the pump. The water level is immediatelyv reduced, but the volute pressure is simultaneously increased due to the pumping action and so the spring remains squeezed, the plunger depressed and the pump continues to operate. When the liquid level is reduced below that necessary to exert a static pressure sufiicient to displace diaphragm 51 with a force, in excess of the switch release force (below the 1" minimum) the plunger extends, displacing the diaphragm 51 toward its at rest position and deactuating the pump. The pressure in the volute is thereupon reduced to that of the static pressure within the sump and the diaphragm 50 assumes its normal position and the pump and control are ready for the cycle to be repeated, all as more fully set fonth in my co-pending application Serial No. 493,631 filed March 11, 1955.

In the past when pumps and controls of the general nature described above have been used together, difficulty has been experienced under certain operating and installation conditions due to the tendency of the pumping sys-- tern to hunt or obtain an operational equilibrium such that the pump is continuously being actuated and deaca tuated for very short cycles. This has resulted in loss of pumping efficiency and unnecessary wear and burden on the parts ofthe pumping system. Such conditions obtain, for example, when the discharge line is of greater diameter than the intake opening and thevolume of the discharge line above the hydrostatic level necessary to cause a complete response in diaphragm is greater than the volume of liquid necessary, upon deactuation of the pump, to raise the liquid level in the sump, for example, to that necessary to cause a complete response in diaphragm 51. In such instances, upon deactuation of the pump, the liquid runs back into the volute chamher from the discharge line at a faster rate than it can run out through the intake opening and into sump. Consequently the volute chamber fills with liquid and the pressure therein becomes equal to the hydrostatic pressure of the liquid within the discharge line. Liquid continues to drain from the discharge line through the volute chamber and into the sump; the volute of returned liquid is sufiicient to cause a full response in diaphragm 5'1. Under the conditions set forth above, this condition obtains while the hydrostatic pressure in the discharge line is sufficient to cause a full response in diaphragm 50 and the switch is closed in the manner set forth above. The pump thereupon actuates, pumping liquid from the sump, into the discharge line. As soon as the pump reduces the liquid level in the sump below that necessary to maintain the response in diaphragm 51 the diaphragm is displaced away from the switch (rightward as viewed) and the pump deactuates. The volume of liquid thus pumped is substantially equal to the volume of liquid which returned to the sump upon the first deactuation of the pump and the volume of liquid in the discharge line upon the second deactuation of the pump is therefore substantially equal to the volume of liquid in the discharge line upon the first deactuation of the pump, and the cycle of stopping and starting or hunting occasioned by the run back and pumping of the same volume of liquid is therefore repeated ad infinitum and without benefit whatever to the pumping system, its function or purpose.

Such hunting depends, inter alia, on the relationship between the diameter, length and head of the discharge line, the diameter of the aperture 44, the cross-sectional area or volume of the sump or bilge, and the predetermined or preload liquid depth selected to cause a maximum response in diaphragm St The diaphragm 56 is preferably determined not with regard to the stated problem of hunting, but with regard to the utility and efliciency of the control as above described. Accordingly, in order to prevent against even the possibility of such hunting in pumping systems embodying my invention, I preferably provide my pump with a novel check valve 61 which is disposed in the volute just forward of the discharge outlet.

The check valve, FIGURES 2 and 4, is adapted to slidably fit into a groove 62 which is provided in the side and top volute walls and to be held therein by the pump bottom cover plate 4% It may therefore be easily replaced, if it becomes damaged or worn during use, by simply loosening the screws 35, removing the bottom assembly 34, sliding the old valve out of the groove 62, placing a new one in the groove and replacing the bottom assembly. As best seen in FIGURE 4, wherein the parts are arranged from rightto. left as viewed from top to bottom in FIGURE 2, the check valve comprises rigid, preferably brass, plates, 64 and 65, which have a periphery of substantially the same shape and size as a crosssection of the volute at the bottom of the groove 62. The plates 64 and 65 are provided with aligned central apertures 67 and 68, respectively, through which the liquid being pumped is forced. These apertures 67 and 68 are as large as conveniently practicable, so as to present small resistance to the, discharge fiow. A rubber gasket 70 having substantially the same peripheral shape as the plates 64 and 65 but being adapted to extend slightly beyond the plates 64 and 65 and bottom edgewise in the groove 62 is provided between the said plates and when assembled prevents liquid from flowing around the edges of the check valve. The gasket is, also, provided with an aperture 71, which is in alignment with the apertures 67 and 68.

A flexible, preferably rubber, flap 73- provides means for controlling the flow of liquid through the check valve. The flap is located on the discharge side of the check valve, lower side as viewed in FIGURE 2, and is adapted to permit liquid to flow from the volute into the discharge line butnot vice versa. The flap is of sufficient size to cover the aperture 68, and is provided with an angled portion 74 which preferably is bent toward the discharge outlet and under backflow pressure aids in insuring a liquid-tight seal between the valve and the bottom plate at A rigid, preferably brass, reinforcing plate '76 of greater size than the aperture 68, is secured to flap 73, as by gluing or vulcanizing. The plate 76 is secured to the discharge side of the flap and is adapted to overlie the aperture 63 and functions to stiffen the flap and prevent the liquid trapped in the discharge line, when pumping stops, from forcing the flap 73 through or bulging it into the'aperturs 68, '71 and 67.

Preferably the check valve members 64, 7t), 65 and 73 have a plurality of aligned holes 77, which provide convenient means for assembling the check valve. A small draw plate 78 having similar aligned holes, overlies a part of the discharge side of the flap 73 and provides a surface upon which the heads of the rivets 80 or other fastening means bear. In operation the flap 73 hinges along a line between the reinforcing plate 76 and draw plate 78.

The valve 61 also functions to increase the efiiciency of the pumping system as a whole by eliminating the unnecessary repumping of the liquid in discharge line which would otherwise return to the sump upon deactuation of the pump.

When a pump embodying my invention and including check valve 61 is not self-priming the liquid rising within the sump and collecting about the pump traps air in the volute and the air so trapped, while transmitting pressures within the volute, may prevent the liquid from entering the volute sufiiciently to prime the pump. Under such circumstances the. control functions in the manner set forth above to actuate the pump (the hydrostatic pressure being transmitted from the liquid to diaphragm 59 by the entrapped air) but once actuated no liquid is pumped, since the pump is not primed, and therefore the pump continues to operate without evacuating any liquid until damaged, stopped, or sufficient hydrostatic pressure is developed in the sump to compress the trapped air sufficiently to permit the pump to become primed.

In order to prevent such air lock and ensure that my pump primes and pumps liquid upon actuation I preferably provide my pump with an air lock relief valve 85. The valve indicated generally at is preferably disposed in the top of the volute, FIGURES 2 and 5, just upstream of the check valve 61 and provides communication between the volute and the exterior of the housing 1. The air lock relief valve 85 preferably comprises means to permit the air, which would otherwise be trapped within the volute by rising liquid, to escape from the volute into the atmosphere exteriorly of the pump and valve means to prevent liquid from so escaping when the same is being pumped.

Preferablyand conveniently the air lock relief valve 35 comprises a small hole, port or vent 86 formed in the top 3 of the volute chamber 1. The vent 86 is in and of itself sufficient to prevent air lock but in addition to permitting air to escape from the volute would, also, permit the liquid to be forced therethrough during the pumping cycle with resultant loss of pumping efiiciency and discharge pressure. Accordingly, valve means is provided for the vent 86 and is adapted to close the vent during the pumping cycle. The valve means preferably and conveniently comprises a flexible closure member 87, such as a rubber flap, which is adapted to extend into the volute at an angle to the top when no liquid is being pumped and to flex and bend against the inside top of the volute and across the vent 86, closing the same, when liquid isbeing pumped and in response to the flow thereof. To this end the flap 87 is secured at its upstream end, as by rivet 88, to the top of the volute and more particularly to a seat 90, which is provided just upstream of vent 86. Seat 90 includes at its downstream end a slanting surface 93 which is adapted to properly position the flap 87 so that the same is disposed and reacts in the manner hereinbefore set forth.

With the pump at rest, liquid collects about the pump, its level rises to the level of the inlet 44 and then fills the volute by displacing the air, which would otherwise be trapped in the volute, out through the open vent 86, thereby insuring that the pump primes and pumps liquid upon actuation by the control. Upon actuation the flow of liquid in the volute and out the discharge bends or forces the flap '87 over the open end of the vent thereby preventing liquid from being forced through the vent.

A shield 94 may be disposed over the vent to deflect any liquid which may escape through the vent.

Modifications, changes and improvements to my invention may occur to those skilled in the art all within the teaching and precepts hereof, and I do not wish to be limited in the scope of my patent to the precise embodiments herein particularly illustrated and described nor in any manner inconsistent with the progress by which my invention has promoted the art.

I claim:

1. A submersible pump comprising a housing forming a volute chamber and a passageway having a discharge outlet extending therefrom, an impeller mounted for rotation within said chamber and adapted to pump fluid from said volute chamber through said passageway and outlet, a motor for driving said impeller, a pressure responsive control connected with said volute chamber and responsive to a predetermined static pressure within said volute chamber to actuate said motor and impeller, and valve means in said passageway intermediate said chamber and outlet and adapted to prevent flow of fluid through said outlet and passageway into said volute. chamber.

2. The combination according to claim 1 in which said pump also comprises air lock relief means disposed upstream of said valve means and providing communication between said passageway and the exterior of said housing.

3. The combination according to claim 2 in which said air lock relief means comprises a vent extending through said housing upstream of said valve means to the exterior of said housing and air lock relief valve means for controlling said vent, said air lock relief valve means being adapted to close said vent when liquid is pumped out through said outlet.

4. The combination according to claim 3 in which said air lock relief valve means comprises a flexible closure member secured to the interior of said housing upstream ofsaid vent, said closure member normally extending away from said housing and being adapted to bend across and close said vent in response to the flow of liquid.

pumped out through said outlet.

5. A submersible pump comprising a housing defining a volute chamber and a passageway extending therefrom and having a discharge outlet, a cover plate closing one side of said volute chamber and passageway, an impeller mounted for rotation within said chamber and adapted to pump fluid from said volute chamber through said passageway and outlet, a motor for driving said impeller, a pressure responsive control in communication with said volute chamber and responsive to a predetermined pressure within said volute chamber to actuate said motor and impeller, valve means in said passage intermediate said chamber and outlet and adapted to prevent how of fluid through said outlet and passageway into said volute chamber, and air lock relief means disposed upstream of said valve means, said valve means comprising groove means lying in a plane transverse of said passageway, 21 plate having an aperture therein and a closure member, said apertured plate having its peripheral edges in said groove means and being held therein by said cover plate, said closure member being on the downstream side of and adjacent said apertured plate and being hinged relative to said aperture and controlling the flow of fluid through said aperture and being adapted to open said aperture when said impeller is pumping fluid through said aperture in response to the pressure thereof and to close and cover said aperture in response to fluid pressure within said passageway downstream of said apertured plate when said impeller ceases to pump fluid through said aperture, and said air lock relief means providing communication between said passageway and the exterior of said housing.

6. The pump according to claim 5 in which said apertured plate comprises a flat sealing member sandwiched between two stiffening members and of greater external size than said stiffening members whereby to form a fluid tight seal in said groove means and said closure member comprises a flexible sealing member secured to said plate and adapted to hinge relative thereto and a rigid plate of greater area than said aperture and secured to said flexible member on the downstream side thereof and adapted to overlie said aperture when said closure member is closed.

7. In a pump having a housing and a cover plate defining a volute chamber and a passageway having an outlet leading therefrom, the improvement of valve means in said passageway intermediate said outlet and volute chamber, said valve means comprising internal groove means disposed in a plane transverse of said passageway, a plate having an aperture therein and a closure member, said apertured plate having its peripheral edges in said groove means, said closure member being on the downstream side of and adjacent said apertured plate and being hinged relative to said aperture and controlling the flow of fluid through said aperture.

8. The pump according to claim 7 in which said apertured plate comprises a flat sealing member sandwiched between two stiflening members and of greater external size than said stiffening members whereby to form a fluid tight seal in said groove means and said .closure member comprises a flexible sealing member secured to said plate and adapted to hinge relative thereto and a rigid plate of greater area than said aperture and secured to said flexible member on the downstream side thereof and adapted to overlie said aperture when said closure member is closed.

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